2121011111 has 2 divisors, whose sum is σ = 2121011112. Its totient is φ = 2121011110.

The previous prime is 2121011099. The next prime is 2121011141. The reversal of 2121011111 is 1111101212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121011111 - 2²⁶ = 2053902247 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121011092 and 2121011101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121011141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060505555 + 1060505556.

It is an arithmetic number, because the mean of its divisors is an integer number (1060505556).

Almost surely, 2^2121011111 is an apocalyptic number.

2121011111 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121011111 is an equidigital number, since it uses as much as digits as its factorization.

2121011111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 11.

The square root of 2121011111 is about 46054.4363878226. The cubic root of 2121011111 is about 1284.8358556300.

Adding to 2121011111 its reverse (1111101212), we get a palindrome (3232112323).

The spelling of 2121011111 in words is "two billion, one hundred twenty-one million, eleven thousand, one hundred eleven".